Patent Document 1 discloses a LED submount for mounting a semiconductor light emitting diode (LED element) onto a mother substrate. The LED submount described in Patent Document 1 forms a base substrate of Si for the LED submount, and a reflective film (Al thin film) between the substrate and an LED element mounted on the substrate. Thus, light output from the LED element toward the base substrate of Si is reflected by the reflective film. As a result, the luminescent efficiency of the LED element is increased.
Patent Document 1: Japanese Patent Application Laid-Open No. 2006-86176